How Wrought Iron is Made

Wrought Iron Defined

Wrought iron is a type of iron that has additives that make it malleable and it also gives it a very low corrosion rate. The actual term “wrought iron” not only refers to the type of iron but also refers to the actual process in which it is made. Wrought iron is now used for decorative fencing and molding for doors, windows and furniture.

How Wrought Iron Was Made Hundreds of Years Ago…

A couple hundred years ago wrought iron was made by the bloomery process. The bloomery process was designed to smelt iron from its oxides by way of a large furnace. The bloomer process also included mixing iron ore (the main raw material in the manufacturing in wrought iron) and charcoal in a forge (a place where metals are heated at high temperatures) and heating the mixture at a temperature beneath the melting point of iron. This process would allow the slag that is found in the ore to be run out of the forge. This process however does not make untainted wrought iron. The iron ore now would have a squishy and malleable texture to it and would have to go through the forge to be fired a second time. After it is fired a second time it can be molded and shaped into forms that we see today and recognize as wrought iron.

The Aston Process…

While the process described above worked well for hundreds of years, the current method for manufacturing wrought iron is a process that is now known as the Aston process. A man named James Aston designed a method in 1925 that involved taking molten steel from something known as a Bessemer Converter and then transferring it to a slag that was much cooler in temperature. Due to the low and cool temperature of liquid slang, when the molten steel is transferred the dissolved gases are transformed. This changes the nature of the material to something that is spongier in form and must be finished by being shingled and rolled (shingled and rolled is the process in which it is given shape).

Now a Days….

In 1969 the last steel plant closed. The manufacturing and production of wrought iron has been demonstrated to be at least twice the cost of low carbon steel. Now, some actual wrought iron is still used for restorative work but this is only by recycled scrap wrought iron.

Resources:

http://en.wikipedia.org/wiki/Wrought_iron#The_Aston_process

http://www.ehow.com/how-does_4924436_how-wrought-iron-made.html

http://www.wisegeek.com/what-is-wrought-iron.htm

http://www.wrought-iron-crafts.com/wrought-iron-process.html